Wastewater treatment plant performance

Evaluates the performance of each unit of a wastewater treatment plant based on hydraulic loadings, solid flux loadings, food/microorganism ratios, sludge age, settleability, and related parameters. 

It should be noted that the total loss of head of a filter bed is in inverse ratio to the depth of penetration of the matter in suspension. In a normal wastewater treatment plant, the water is brought onto a series of rapid sand filters and the impurities are removed by coagulation-flocculation-filtration. Backwashing is typically performed in the counterfiow mode, using air and water. One type of common filter is illustrated in Figure 6, consisting of closed horizontal pressurized filters. 

Hamilton Standard of the U.S. EPA has reported several coil coating plants wastewater treatment case histories.8,9 A full-scale wastewater treatment plant system has performed well for treatment of the wastewater generated from coil coating steel subcategory operations. The process principles and operational data of the full-scale treatment of a steel subcategory wastewater are summarized herein for the convenience of readers ... 

A sewer network and any corresponding treatment have traditionally been separately designed and operated. Two different and separate functions have been dealt with the sewer system must collect and convey the wastewater to the treatment plant, and the treatment plant must reduce pollution load into the receiving water according to the quality standards set. Consequently, sewers are often just considered input systems at the boundaries where they are connected with wastewater treatment plants and overflow structures that discharge untreated wastewater into watercourses during rainfall. This traditional approach to sewer performance needs considerable improvement. 

A new in situ probe [25] was presented for the continuous measurement of ammonium and nitrate in a biological wastewater treatment plant. Based on the use of electrochemical measurement, the sensor can be immersed and requires minimum maintenance. The tests carried out to compare its performance with those of other procedures (including UV for nitrate) showed that the results were rather close, with a detection limit of 0.1 mg L 1 for both analytes. 

Marcomini et al. [25] performed the protonation of the carboxylic groups of the SPC. This technique termed ion suppression effect chromatography enabled the individual elution of the SPC contained in a primary sludge from a wastewater treatment plant. The quantification of the SPC was performed under the assumption that the signals detected by fluorescence before the elution of the LAS (with the exception of NPEC) correspond solely to SPC. 

In any case the wastewater will finally be fed into rivers, lakes, or the sea thus some wastewater treatments have to be performed before the textile effluents are released either to the communal wastewater treatment plant (CWWT) or into the rivers, lakes, and so on. Normally physical and (bio-) chemical treatments (e.g., adjustment of pH, temperature, sedimentation, flocculation) are performed in the textile plant, while the following biological treatment (aerobic, anaerobic degradation) is performed either in the textile plant or in a CWWT. The site of the biological treatment is dependent on the location of the textile plant however, a biological treatment of textile effluents preceding release into surface water is state of the art. 

Development of extraction conditions for LAS was performed using sludge from a municipal wastewater treatment plant, and agricultural soil from a field which had been used for disposal of sewage sludge several months prior to... 

Biomass obtained from the wastewater treatment plant of Middle East Technical University (METU) was used as seed in the experiments. In the acclimation of MOs to HMs, maximum concentrations of Cu2+ and Zn2+ reached during acclimation were decided from previous work [17,21], The literature showed that when these metals were present individually in the system, ASP failed to operate at steady state values of 15 mg/L for Cu2+ and 90 mg/L for Zn2+, respectively [5], Therefore, one-third of threshold concentrations of these metals (that is, 5 mg/L for Cu2+, and 30 mg/L for Zn2+) were used to constitute the combined threshold concentration for mixtures of copper and zinc ions. Acclimation experiments were performed by gradually increasing the concentrations of Cu2+ and Zn2+ to two, three and four times their combined threshold concentration. The optimum condition for a successful acclimation providing the growth of healthy MOs, as observed from the increase in turbidity values, was obtained at the concentrations corresponding to twice their combined threshold concentration [21],... 

The emission inventory of dioxin-like compounds in South Korea was determined during two preliminary studies (KMOE, 2001, 2002a). For emission factors, the preliminary study (KMOE, 2001) adopted measured values for waste incinerators and the values of UNEP chemicals Toolkit (UNEP Chemicals, 2001) for the other sources. Estimated PCDDs/DFs emission in 1999 ranged from 1163 to 1595 g I-TEQ yr-1 due to uncertainties in emission factors and activities (Table 2.6). Besides the preliminary estimate, since the late 1990s extensive measurements of PCDDs/ DFs have been performed at waste incinerators and the emission data by 2004 had been compiled for 1800 incinerators. Moreover, nationwide industrial sources have been investigated every year since 2001 34 fer-rous/non-ferrous metal production factories in 2001, 114 non-ferrous metal and mineral production factories in 2002, 73 chemical/energy/ landfill factories and crematories in 2003, and 63 municipal wastewater treatment plants and 9 types of vehicles in 2004. By 2005, measurements of total dioxin emissions had been made on 288 industrial sources. Based on these measurements, KMOE made the first official estimate of PCDDs/DFs emission in South Korea. It has been estimated that the total PCDDs/DFs emission was 1021 g I-TEQ yr-1 in 2001 (KMOE website) (Table 2.6). This emission was approximately 62% of that... 

Perez-Cid et al. (1996) compared Tessier and BCR sequential extractions for the speciation of Cu, Cr, Pb, Ni and Zn in sludge from an urban wastewater treatment plant and found similar performance for the two procedures. Zufiaurre et al. (1998) later demonstrated, using the Tessier method and PCA, that, since most metals in a sludge were bound to oxidisable and residual fractions, bioavailability was likely to be very low. 

Several pollution control technologies at the refinery promote cross-media transport, the transfer of pollutants from one medium to another. Wastewater, for example, may contain hydrocarbons that volatilize into the air at the refinery, the wastewater treatment plant converted these waterborne hydrocarbons into 2400 tons/year of sludge, which were recycled to the coker. Cross-media transport from air to water is not significant for hydrocarbons or chemical that are only slightly soluble in water (Allen et al, 1989). Studies performed by the National Center for Intermedia Transport at the University of California, Los Angeles, for instance, showed that most hydrocarbons released into the air do not transfer rapidly into other media. Therefore, ignoring intermedia transfer when examining air quality impacts is a reasonable analytical approach. Water-soluble compounds, such as methanol and MTBE, can transfer from air into water and soil media under certain conditions (Cohen et al., 1991). 

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